WATCH: Wheels come off for Alonso and McLaren (literally)
Any pre-season optimism among long-suffering McLaren fans may have been punctured earlier than expected in 2018, after Fernando Alonso's first test run in Barcelona came to an abrupt halt on Monday.
A two-time world champion with Renault in 2005 and 2006, the Spaniard has toiled without success since leaving Ferrari for McLaren.
Finishes of 17th, 10th and 15th for Alonso in the last three drivers' championships demonstrate the extent of the team's decline.
And hopes of a resurgence in 2018 were quickly dented by the sight of the 36-year-old abruptly leaving the track and grinding to a stop on the gravel at the Circuit de Barcelona-Catalunya after a wheel became detached from the new MCL33 after just a few laps.